The use of a radiant heating apparatus will be discussed in conjunction with scarifiers and patchers. However, the use of a radiant heater of the present invention is not limited to scarifiers and patchers.
The term "scarifier" denotes a machine that travels slowly along a roadway while heating the existing asphalt to a relatively high temperature. It then loosens the hot asphalt and finally smooths down the loosened hot material to form a reconditioned and resurfaced roadway.
The term "patcher" denotes a machine that heats a small area of asphalt to a relatively high temperature. The treated area is hand raked and finally rolled to produce a reconditioned patch of asphalt.
A critical component of scarifiers and patchers is the heater assembly for applying heat to the old roadway surface. It is desirable to apply as much heat as possible to the asphalt, and to do so as quickly as possible, because the amount of heat that can be transferred to the asphalt per unit time will determine how fast the machines can recondition a roadway surface. The efficiency of heat transfer will also determine the depth to which the asphalt can be heated.
The other major component of a radiant heating apparatus is the fuel-air supply system. This system supplies the necessary high pressure propane gas into the burner unit. It is important that the propane gas be supplied at a high pressure in order to produce a 100% premix of air and propane gas.